4CEL:
reference: Activity studies and crystal structures of catalytically deficient mutants of cellobiohydrolase I from Trichoderma reesei., Stahlberg J, Divne C, Koivula A, Piens K, Claeyssens M, Teeri TT, Jones TA, J Mol Biol 1996 Nov 29;264(2):337-49. PMID: 8951380

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).